Blender Boolean is not working as expected

I was trying to show scroll effect in blender.
I just created array of blocks(Posts). and on screen i created another block(Cutter) with view port BOUND then in select posts and Add modifier > Boolean > Select the Cutter object > Intersect
But the Problem is

It Is showing object which is out from top until it fully exit the block and Show object from bottom till it fully enter. It is not showing the part of post intersecting.

Some how i was not able to push images but sharing the link https://developer.blender.org/T75267

Just put the “Bevel modifier” at bottom and you could scroll.
Also your Posts are messed up, apply scale and merge.

Can you please tell What do you mean by scale and meagre ? Is it a function or so in blender ?

Try if slightly increasing the width of the Boolean cutter helps.

The mesh is not valid, it has double vertices/faces. Fix that by merge the doubles.
Also bevel dont work if the scale is not applied.